Inactivation and injury of Escherichia coli O157 : H7 and Staphylococcus aureus by pulsed electric fields

DAMAR S., Bozoglu F., Hizal M. , Bayindirli A.

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY, cilt.18, ss.1-6, 2002 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 18 Konu: 1
  • Basım Tarihi: 2002
  • Doi Numarası: 10.1023/a:1013900222139
  • Sayfa Sayıları: ss.1-6


Two pathogenic microorganisms Escherichia coli O157:H7 and Staphylococcus aureus, suspended in peptone solution (0.1% w/v) were treated with 12, 14, 16 and 20 kV/cm electric field strengths with different pulse numbers up to 60 pulses. Pulsed electric field (PEF) treatment at 20 kV/cm with 60 pulses provided nearly 2 log reduction in viable cell counts of E. coli O157:H7 and S. aureus. S. aureus cells were slightly more resistant than E.coli O157:H7 cells. The results related to the effect of initial cell concentration of E. coli O157:H7 on the PEF inactivation showed that more inactivation was obtained by decreasing initial cell concentration. Any possible injury by PEF was also investigated after applying 20 kV/cm electric field to the microorganisms. As a result, it was determined that there was 35.92 to 43.36% injury in E. coli O157:H7 cells, and 17.26 to 30.86% injury in S. aureus cells depending on pulse number. The inactivation results were also described by a kinetic model.